For the last sixty years, magnetic tapes have been used for data storage, backup and restoration of analog and digital information. Over these years, data has been stored on magnetic tapes having various tape formats, and using various compression/validation/correction algorithms and with various reading/writing devices. Years after the storage of data on such magnetic tapes, technical obstacles regarding successful reading of old or damaged magnetic tapes have appeared.
One example of such technical obstacles relates to tracks that were written on magnetic tapes by computers that had no operating systems, resulting in a lack of documentation in the mapping of recorded bits to numbers and letters. This is problematic in that the recorded bits were encoded with non-standard character sets, as opposed to standard character sets such as, for example, ASCII and EBCDIC, in use today.
Another example of such technical obstacles relates to tracks on magnetic tapes being misaligned or magnetic tapes that had momentarily shifted in the tape path thereby causing erratic skewing issues. Both of these cases result in missing bits on tracks causing parity errors or bit loss upon reading of the magnetic tape.
An additional example of such technical obstacles relates to the proximity of layers of a magnetic tape on a tape spool. This proximity can cause the imprint of magnetic information of one layer of a tape on an adjacent layer or layers of the magnetic tape, thereby shifting copies of a signal backwards and/or forwards along the magnetic tape. Such shifting of copies of the signal can give false positives for bit determination.
Another example of such technical obstacles relates to the use of induction heads to read magnetic tapes. Induction heads require the magnetic tape to be read at a specific speed for which the magnetic tape was originally designed. In addition, metal oxide present on magnetic tapes might shed from the tape binder due to sticky tape syndrome.
An additional example of such technical obstacles relates to magnetic tapes that have been damaged magnetically and/or mechanically and including print through and bit drop out errors.
Another example of such technical obstacles relates to the presence of weak bits on magnetic tapes.
Therefore, there is a need for a system and method for reading a magnetic tape that helps in overcoming at least one (and preferably more) of the technical obstacles mentioned above.